1. Field of the Invention
The present invention relates to a headband adjustment device and particularly to an adjustment device attached to a head enclosing apparatus especially such as lunettes for loosening or tightening a headband by way of a resilient adjustment plate.
2. Description of Related Art
It is quite often that a variety of head wearable tools such as headbands, helmets, lunettes, protective spectacles and headlamps are used in our daily lives. The major requirements of the head wearable tools are in that they have to be comfortable during being worn and the tightness thereof has to be adjustable so as to fit different head measurements. In fact, adjustable tightness can enhance the wearing comfort to some extent.
Taking the conventional lunettes as an example, the headband adjustment device is an essential part for the lunettes and disposed at both lateral sides of the lunettes so as to be adjusted the tightness thereof. However, it is inconvenient that the adjustment device at both lateral sides of the lunettes has to be adjusted and the adjustment device has spoiled the facial smoothness of the wearer. In addition, the adjustment device has increased the gross size of the lunettes such that they become not easy for the lunettes to be worn or carried about.
Another type of conventional lunettes has the adjustment device be disposed at the back of the head but it is provided with a complicated way for tightness adjustment.